/* FCE Ultra - NES/Famicom Emulator
 *
 * Copyright notice for this file:
 *  Copyright (C) 2002 Xodnizel
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "mapinc.h"

static uint8 cmd, mir, rmode, IRQmode;
static uint8 DRegs[11];
static uint8 IRQCount, IRQa, IRQLatch;

static SFORMAT Rambo_StateRegs[] = {
	{ &cmd, 1, "CMD" },
	{ &mir, 1, "MIR" },
	{ &rmode, 1, "RMOD" },
	{ &IRQmode, 1, "IRQM" },
	{ &IRQCount, 1, "IRQC" },
	{ &IRQa, 1, "IRQA" },
	{ &IRQLatch, 1, "IRQL" },
	{ DRegs, 11, "DREG" },
	{ 0 }
};

static void FP_FASTAPASS(2) (*setchr1wrap)(unsigned int A, unsigned int V);

static void FP_FASTAPASS(1) RAMBO1_IRQHook(int a) {
	static int smallcount;
	if (!IRQmode) return;

	smallcount += a;
	while (smallcount >= 4) {
		smallcount -= 4;
		IRQCount--;
		if (IRQCount == 0xFF)
			if (IRQa) X6502_IRQBegin(FCEU_IQEXT);
	}
}

static void RAMBO1_hb(void) {
	if (IRQmode) return;
	if (scanline == 240) return;     /* hmm.  Maybe that should be an mmc3-only call in fce.c. */
	rmode = 0;
	IRQCount--;
	if (IRQCount == 0xFF) {
		if (IRQa) {
			rmode = 1;
			X6502_IRQBegin(FCEU_IQEXT);
		}
	}
}

static void Synco(void) {
	int x;

	if (cmd & 0x20) {
		setchr1wrap(0x0000, DRegs[0]);
		setchr1wrap(0x0800, DRegs[1]);
		setchr1wrap(0x0400, DRegs[8]);
		setchr1wrap(0x0c00, DRegs[9]);
	}else {
		setchr1wrap(0x0000, (DRegs[0] & 0xFE));
		setchr1wrap(0x0400, (DRegs[0] & 0xFE) | 1);
		setchr1wrap(0x0800, (DRegs[1] & 0xFE));
		setchr1wrap(0x0C00, (DRegs[1] & 0xFE) | 1);
	}

	for (x = 0; x < 4; x++)
		setchr1wrap(0x1000 + x * 0x400, DRegs[2 + x]);

	setprg8(0x8000, DRegs[6]);
	setprg8(0xA000, DRegs[7]);

	setprg8(0xC000, DRegs[10]);
}


static DECLFW(RAMBO1_write) {
	switch (A & 0xF001) {
	case 0xa000:
		mir = V & 1;
		setmirror(mir ^ 1);
		break;
	case 0x8000:
		cmd = V;
		break;
	case 0x8001:
		if ((cmd & 0xF) < 10)
			DRegs[cmd & 0xF] = V;
		else if ((cmd & 0xF) == 0xF)
			DRegs[10] = V;
		Synco();
		break;
	case 0xc000:
		IRQLatch = V;
		if (rmode == 1)
			IRQCount = IRQLatch;
		break;
	case 0xc001:
		rmode = 1;
		IRQCount = IRQLatch;
		IRQmode = V & 1;
		break;
	case 0xE000:
		IRQa = 0;
		X6502_IRQEnd(FCEU_IQEXT);
		if (rmode == 1)
			IRQCount = IRQLatch;
		break;
	case 0xE001:
		IRQa = 1;
		if (rmode == 1)
			IRQCount = IRQLatch;
		break;
	}
}

static void RAMBO1_Restore(int version) {
	Synco();
	setmirror(mir ^ 1);
}

static void RAMBO1_init(void) {
	int x;
	for (x = 0; x < 11; x++)
		DRegs[x] = ~0;
	cmd = mir = 0;
	setmirror(1);
	Synco();
	GameHBIRQHook = RAMBO1_hb;
	MapIRQHook = RAMBO1_IRQHook;
	GameStateRestore = RAMBO1_Restore;
	SetWriteHandler(0x8000, 0xffff, RAMBO1_write);
	AddExState(Rambo_StateRegs, ~0, 0, 0);
}

static void FP_FASTAPASS(2) CHRWrap(unsigned int A, unsigned int V) {
	setchr1(A, V);
}

void Mapper64_init(void) {
	setchr1wrap = CHRWrap;
	RAMBO1_init();
}
